In a typical wireless communication network, wireless terminals, also known as mobile stations and/or user equipments (UEs), communicate via a Radio Access Network (RAN) to one or more core networks. The RAN covers a geographical area which is divided into cell areas, with each cell area being served by a base station, e.g., a radio base station (RBS), which in some networks may also be called, for example, a “NodeB (NB)” or “eNodeB (evolved NB)”. A cell is a geographical area where radio coverage is provided by the radio base station at a base station site or an antenna site in case the antenna and the radio base station are not collocated. Each cell is identified by an identity within the local radio area, which is broadcast in the cell. Another identity identifying the cell uniquely in the whole mobile network is also broadcasted in the cell. The base stations communicate over the air interface operating on radio frequencies with the wireless terminals within range of the base stations. Transmissions from the wireless terminals to the radio base station are defined as uplink (UL) transmissions and transmissions from the radio base station to the wireless terminal is defined as downlink (DL) transmissions.
In some versions of the RAN, several base stations are typically connected, e.g., by landlines or microwave, to a controller node, such as a radio network controller (RNC) or a base station controller (BSC), which supervises and coordinates various activities of the plural base stations connected thereto. The RNCs are typically connected to one or more core networks.
A Universal Mobile Telecommunications System (UMTS) is a third generation mobile communication system, which evolved from the second generation (2G) Global System for Mobile Communications (GSM). The UMTS Terrestrial Radio Access Network (UTRAN) is essentially a RAN using Wideband Code Division Multiple Access (WCDMA) and/or High Speed Packet Access (HSPA) for user equipments. In a forum known as the Third Generation Partnership Project (3GPP), telecommunications suppliers propose and agree upon standards for e.g. third generation networks and further generations, and investigate enhanced data rate and radio capacity.
Specifications for the Evolved Packet System (EPS) have been completed within the 3GPP and this work continues in the coming 3GPP releases. The EPS comprises the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), also known as the Long Term Evolution (LTE) radio access, and the Evolved Packet Core (EPC), also known as System Architecture Evolution (SAE) core network. E-UTRAN/LTE is a variant of a 3GPP radio access technology wherein the radio base stations are directly connected to the EPC core network rather than to RNCs. In general, in E-UTRAN/LTE the functions of a RNC are distributed between the radio base stations, e.g., eNodeBs in LTE, and the core network. As such, the RAN of an EPS system has an essentially “flat” architecture comprising radio base stations without reporting to RNCs.
In a Bluetooth Special Interest Group (SIG), a new feature, namely, Bluetooth Low Energy (BLE) Long Range is being standardized for applications where the best possible performance and range are required. Forward error correction (FEC) coding and spreading are being introduced to improve the receiver sensitivity and range. To fully take advantage of these improvements, it is desirable that the new features, e.g. coding and spreading, being introduced work well in many different operating scenarios. Since Bluetooth operates in an unlicensed band, interference from other Bluetooth devices or other WiFi devices sharing the same unlicensed band can be expected. In many cases, such interference is bursty in the sense the interference may not last for the entire burst duration of the desired signal. The bursty interference may also occur when the entire desired burst is interfered, but the worst interference only last for a fraction of the burst duration. For such situations, an interleaver may be introduced following the encoder operation to put the data bits into a different order to add robustness to bursty interference.
Interleaver patterns need to be designed carefully to support e.g. BLE Long Range (BLR) operation. For example, a Packet Data Unit (PDU) Header of a packet, which PDU header comprises the information about a PDU Payload length, may be encoded in a same codeword as a PDU payload of the packet. Interleaver pattern however is typically determined by a length of the codeword. The PDU Payload length information and PDU Payload are coded together, and interleaving is used to improve robustness to bursty interference. However, the performance of the wireless communication network may be limited as the receiving device does not know the codeword length and cannot perform decoding operation properly.